Don't know if it hurts or helps that I have a compressor before and after the C4, one on a light setting on the EHX Battalion at the front of my chain, then the EHX Platform right after the C4 to take the stereo out. Synth pedals always seem to have the most variable responses, so I try to tame it as best as I can before the envelope filters and reverb.
And at home I've alternated between using my GK MB115 (and blasting my head off in the process), and using headphones (and blasting my ears in the process, but found this to be quite useful for detecting suboctaves that could be devastating to a speaker and that I don't pick up with the full bore sound of the MB115 in a small room). Rehearsal space has different volume level, and each venue offers its own challenges and volume settings, so this is likely to be a tricky thing, but I really like the idea of always having one of the two knobs set for volume when publishing the preset, so that it can easily be dialed back without affecting the volume you want to have it pretty much set for on the top left volume/sensitivity knob. While rehearsing I didn't have any volume blasts in switching, just some sounds to be a bit louder than others, which is normal. I still fight volume battles with my Markbass SuperSynth. (By the way, that seems to be an underrated pedal, don't hear it spoken about much, but it tracks extremely well, does some polyphony, has a good range of sounds, a good desktop editor. Paired with an envelope filter, it's just as badass as the Deep Impact and C4...) I anticipate the volume battles will be lessened with the C4 the more I use it, but don't expect it to disappear completely any more than I do volume struggles or wars on stage and in practice.